Switch



C. R. RICH June 20, 1933.

SWITCH Filed May 21, 1931 l m Tw,

INVENTOR.

WI fr tess/ A TTORNEYJ.

Patented June 20, 1933-- UNITED STATES PATENT OFFICE CLAUDE R. RICII, OF GRAND RAPIDS, MICHIGAN, ASSIGNOR TO TEESDAIJE MANUFAC- TURING COMPANY, OF GRAND RAPIDS, MICHIGAN, A CORPORATION OF MICHIGAN swrrcn Application filed May 21,

The present invention relates to electric switches and more particularly to automatically operated snap switches.

The main objects of the invention are to provide a thermally operated snap switch; to provide such a snap switch having double breaking contact points; to provide a resistance coil heated by an electrical overload for operating the thermally controlled snap switch; and, to provide a switch of the character above outlined having manually opperable means for closing the circuit after it has been automatically broken.

An illustrative embodiment of the invention is shown in the accompanying drawing, wherein:

Figure 1 is a top plan view of the snap switch;

Figure 2 is a side elevational view thereof;

Figure 3 is a sectional View taken on line 3-3 of Figure 1;

Figure 4 is a fragmentary side elevational view of the switch viewed from the side opposite that shown in Figure 2; and,

Figure 5 is an end elevational View thereof.

Referring to the drawing in which like numerals designate the same parts in the several views, a base plate 1 for the switch, preferably of a non-electrical conducting material, has a pair of terminal connections 2, 3 of conventional type for securing electrical lead wires 4, 5.

A circuit breaking element 6, here shown as a bell crank lever, for manually closing the-circuit after it has been broken, is preferably of non-electrical conducting material and a pair of spring contact plates 7, 8 are secured on opposite sides of the lever arm 9 by a pair of electrical conducting pins 10, 11. This bell crank lever is pivotally connected to the base plate in any suitable manner as by the adjusting screw 12 and a spring element 13 secured to the base plate and to w the lever causes the lever to assume the position shown in dotted lines in Figure 1 when the circuit is broken as is hereinafter described. The lever is interposed between a pair of spaced angularly ,disposed circuit making points 14, 15 which are respectively 53 secured to the base plate by means of the ter- 1931. Serial No. 538,909.

minal connection 2 and to the bracket 16 as by the rivets.

The bracket 16 has a laterally projecting portion 17 and a bifurcated thermally re-' sponsive element 18, preferably of bi-m'etallic sheet metal stock, has one of its ends secured to the laterally projecting portion 17 of the bracket 16 as by the screw 19 and its other end is secured to the base plate as by the rivet 20. This thermally responsive element 18 is provided with a hook 21 at its closed end which is adapted to hook over the lever arm 9 as best shown in Figure 1.

A resistance coil 22 of nichrome wire or the like, is disposed adjacent the thermally responsive element 18 to which it is connected at one end as by the screw 23 and at its other end to the terminal connection 3.

In operation, the circuit is closed as best shown in Figure 1. An electrical overload, however, in passing through the resistance coil, causes the same to heat which flexes the thermally responsive element to the position shown in dotted lines in Figure 1. The spring actuated bell crank lever is thus caused to tilt to the position shown in dotted lines in Figure 1 which breaks the circuit at both circuit making contact points. Thus, although one spring contact pomt may become struck, fused or corroded, it is reasonably certain that the other spring contact will break and the circuit will thereby be opened. After the thermally responsive element has sufiiciently cooled the circuit may again be completed by the manual manipulation of the bell crank lever.

It will thus be seen that a thermally opera-ted snap switch is herein show and described which has double circuit breaking contact points and that manually operable means is provided for closing the circuit after it has been automatically broken.

While but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted Without departing from the spirit of this invention as defined by the following claims.

I claim:

1. In a device of the class described: an electric circuit having spaced contact points; a turnably mounted switch having electrically connected contact points on the opposite sides respectively of its axis of turning and contacting the first-mentioned contact points respectively in the normal turned position of the switch to close the circuit; a thermally operated catch normally engaging the switch to releasably hold the same in its circuitclosing position; a resistance in the circuit adjacent the catch adapted to thermally operate the same to release the switch from its circuit-closing position by an abnormally great amount of electric current in the circuit; means for automatically turning the switch when released by the catch to circuit-opening position, the switch having an integral handle portion for manually returning the switch to circuit-closing position.

2. In a device of the class described: an electric circuit having spaced contact points; a 'turnably mounted switch having electrically connected spring contact points on the opposite sides respectively of its axis of turning and contacting the first-mentioned contact points respectively in the normal turned position of the switch to close the circuit; a thermally operated catch normally engaging the switch to releasably hold the same in its circuit-closing position; a resistance in the circuit adjacent the catch adapted to thermallyoperate the same to release the switch from its circuit-closing position by an abnormally great amount of electric current in the circuit; means for automatically turning the switch when released by the catch to circuit-opening position, the switch having an integral handle portion for manually returning the switch to circuit-closing position.

In testimony whereof I have hereunto set my hand at Grand Rapids, Michigan, this 15th day of May, 1931.

, CLAUDE R. RICH. 

